According to the man who flew US president Barack Obama during his 2008 campaign tour, virtually all pilots believe in UFOs.

Andrew Danziger, a veteran pilot with 28 years of experience in the cockpit has also admitted he's had his own brush with the unexplained.

The American pilot says he saw a white disc flying through the sky during a standard flight between Kansas and Iowa in April 1989. The white disc then changed into a "giant red ball" and glowed for about 30 seconds before disappearing into the clouds.

According to Danziger, both he and the captain who was also in the cockpit saw the spooky alien craft for about 40 minutes before it began to change colour and disappeared.

"It looked similar to the moon faintly visible though thin fog, except the two were visible at the same time on opposite sides of our cockpit," Danziger told the New York Daily News.

"While neither of us had any idea what we had saw one thing we were certain of, it wasn't from here," he said.

He says that when he reported the sighting, he was told that many pilots often spot unidentified flying objects while traversing the skies.

"We knew through the grapevine that pilots weren't supposed to talk about UFOs so we swore the station agent on duty to secrecy and agreed not to talk about our incident to any of our co-workers."

But Danziger is sure that he isn't the only airman to have spotted an unexplained craft in the skies.

"I'm not going too far out on a ledge to say that virtually all pilots believe in UFOs," he said.